Racehorse trainer Charlie Brooks admitted his "foolish" behaviour in stashing lesbian porn DVDs and computer equipment in the underground car park of his London flat while his wife was under arrest.
But the 51-year-old denies perverting the course of justice with Mrs Brooks and News International security chief Mark Hanna in 2011.
Lawyer Neil Saunders, QC, in a closing speech, cited an episode when one of Brooks's friends found him frothing at the mouth after drinking washing up liquid as evidence of his propensity for "daft" acts.
Mr Saunders told jurors: "What he did that weekend was stupid and he knows it. While he is a man who is capable of drinking a bottle of Fairy Liquid, he is not capable of committing this offence. On the evidence, we invite you to acquit Mr Brooks."
He was not the sort of character to orchestrate a "fairly complicated and military style operation involving many people embroiled in a web of deceit" with his wife as the "mastermind", jurors were told.
The court heard none of the computer equipment in bags recovered from the car park contained any incriminating evidence.
All seven defendants in the trial, including Mrs Brooks and former News Of the World editor Andy Coulson, deny the charges against them.